1. When someone is playing to not lose instead of playing to win, or playing incredibly defensive with minimal vulnerability i.e. pillar humping, they are playing gay.
2. When someone is playing gimmicky, they are playing gay.

1. That mage is playing gay. All he's doing is cc'ing everything and ice lancing. He's not even trying to win.

2. That rogue is just re-stealthing behind the pillar until his cloak is back up, he's playing so gay.
3. (Upon seeing the other team's comp), "Ok guys we gotta play gay vs them"